Troubleshooting portables that won‘t turn on or start up
Learn how to troubleshoot a PowerBook G4, iBook, or iBook G4 that won't turn on or start up.
Unplug the power adapter from the electrical outlet. Plug it back in. Make sure the electrical outlet is working by plugging in another device (such as a lamp).
Unplug the power adapter from the computer, then plug it back in.
Make sure you are using the adapter that was designed for your computer. If you aren't sure or if you need a new adapter, learn which adapter is appropriate for your computer.
Your computer's battery may need to be recharged. Press the small button on the battery. You should see one to four lights indicating the battery's level of charge. If you see just one light blinking, the battery needs to be recharged.
Disconnect any devices connected to the computer including printers, hubs, third-party keyboards, or mice.
Press the control key, the command key, and the power button simultaneously. If this has any effect, the computer will start up.
Reset the Power Manager. When you do this, you may need to reset the date and time in Date & Time preferences (Mac OS X) or the Date & Time control panel (Mac OS 9).
If you recently installed additional memory, make sure it is correctly installed and is compatible with your computer.
Remove the new memory to see if the computer starts up properly.
If you are still unable to start up your computer after trying each of these steps, you may need to take the computer to an Apple Authorized Service Provider for more assistance.